Circuit interrupting device with reverse wiring protection

ABSTRACT

Resettable circuit interrupting devices, such as GFCI devices, that include reverse wiring protection, and optionally an independent trip portions and/or a reset lockout portion are provided. The reverse wiring protection operates at both the line and load sides of the device so that in the event line side wiring to the device is improperly connected to the load side, fault protection for the device remains. The trip portion operates independently of a circuit interrupting portion used to break the electrical continuity in one or more conductive paths in the device. The reset lockout portion prevents the reestablishing of electrical continuity in open conductive paths if the circuit interrupting portion is non-operational or if an open neutral condition exists.

This application is a continuation of application Ser. No. 10/827,093filed Apr. 19, 2004, (now U.S. Pat. No. 6,864,766) which is acontinuation of application Ser. No. 10/223,284 filed Aug. 19, 2002 (nowU.S. Pat. No. 6,813,126), which is a continuation of application Ser.No. 09/879,563 filed Jun. 11, 2001 (now U.S. Pat. No. 6,437,953), whichis a continuation of application Ser. No. 09/379,138 filed Aug. 20, 1999(now U.S. Pat. No. 6,246,558), which is a continuation-in-part ofapplication Ser. No. 09/138,955, filed Aug. 24, 1998 (now U.S. Pat. No.6,040,967), all of which are incorporated herein in their entirety byreference.

BACKGROUND

1. Field

The present application is directed to reset lockout devices includingresettable circuit interrupting devices and systems such as ground faultcircuit interrupters (GFCI's), arc fault circuit interrupters (AFCI's),immersion detection circuit interrupters (IDCI's), appliance leakagecircuit interrupters (ALCI's), equipment leakage circuit interrupters(ELCI's), circuit breakers, contactors, latching relays and solenoidmechanisms.

2. Description of the Related Art

Many electrical wiring devices have a line side, which is connectable toan electrical power supply, and a load side, which is connectable to oneor more loads and at least one conductive path between the line and loadsides. Electrical connections to wires supplying electrical power orwires conducting electricity to the one or more loads are at line sideand load side connections. The electrical wiring device industry haswitnessed an increasing call for circuit breaking devices or systemswhich are designed to interrupt power to various loads, such ashousehold appliances, consumer electrical products and branch circuits.In particular, electrical codes require electrical circuits in homebathrooms and kitchens to be equipped with ground fault circuitinterrupters (GFCI), for example. Presently available GFCI devices, suchas the device described in commonly owned U.S. Pat. No. 4,595,894, usean electrically activated trip mechanism to mechanically break anelectrical connection between the line side and the load side. Suchdevices are resettable after they are tripped by, for example, thedetection of a ground fault. In the device discussed in the '894 patent,the trip mechanism used to cause the mechanical breaking of the circuit(i.e., the conductive path between the line and load sides) includes asolenoid (or trip coil). A test button is used to test the tripmechanism and circuitry used to sense faults, and a reset button is usedto reset the electrical connection between line and load sides.

However, instances may arise where an abnormal condition, caused by forexample a lightning strike, occurs which may result not only in a surgeof electricity at the device and a tripping of the device but also adisabling of the trip mechanism used to cause the mechanical breaking ofthe circuit. This may occur without the knowledge of the user. Undersuch circumstances an unknowing user, faced with a GFCI which hastripped, may press the reset button which, in turn, will cause thedevice with an inoperative trip mechanism to be reset without the groundfault protection available.

Further, an open neutral condition, which is defined in UnderwritersLaboratories (UL) Standard PAG 943A, may exist with the electrical wiressupplying electrical power to such GFCI devices. If an open neutralcondition exists with the neutral wire on the line (versus load) side ofthe GFCI device, an instance may arise where a current path is createdfrom the phase (or hot) wire supplying power to the GFCI device throughthe load side of the device and a person to ground. In the event that anopen neutral condition exists, current GFCI devices, which have tripped,may be reset even though the open neutral condition may remain.

Commonly owned application Ser. No. 09/138,955, filed Aug. 24, 1998,which is incorporated herein in its entirety by reference, describes afamily of resettable circuit interrupting devices capable of locking outthe reset portion of the device if the circuit interrupting portion isnon-operational or if an open neutral condition exists. Commonly ownedapplication Ser. No. 09/175,228, filed Sep. 20, 1998, which isincorporated herein in its entirety by reference, describes a family ofresettable circuit interrupting devices capable of locking out the resetportion of the device if the circuit interrupting portion isnon-operational or if an open neutral condition exists and capable ofbreaking electrical conductive paths independent of the operation of thecircuit interrupting portion.

Some of the circuit interrupting devices described above have a useraccessible load side connection in addition to the line and load sideconnections. The user accessible load side connection includes one ormore connection points where a user can externally connect to electricalpower supplied from the line side. The load side connection and useraccessible load side connection are typically electrically connectedtogether. An example of such a circuit interrupting device is a GFCIreceptacle, where the line and load side connections are binding screwsand the user accessible load side connection is the plug connection. Asnoted, such devices are connected to external wiring so that line wiresare connected to the line side connection and load side wires areconnected to the load side connection. However, instances may occurwhere the circuit interrupting device is improperly connected to theexternal wires so that the load wires are connected to the line sideconnection and the line wires are connected to the load connection. Thisis known as reverse wiring. In the event the circuit interrupting deviceis reverse wired, fault protection to the user accessible loadconnection maybe eliminated, even if fault protection to the load sideconnection remains.

SUMMARY

The present application relates to a family of resettable circuitinterrupting devices that maintains fault protection for the circuitinterrupting device even if the device is reverse wired.

In one embodiment, the circuit interrupting device includes a housingand phase and neutral conductive paths disposed at least partiallywithin the housing between line and load sides. Preferably, the phaseconductive path terminates at a first connection capable of beingelectrically connected to a source of electricity, a second connectioncapable of conducting electricity to at least one load and a thirdconnection capable of conducting electricity to at least one useraccessible load. Similarly, the neutral conductive path, preferably,terminates at a first connection capable of being electrically connectedto a source of electricity, a second connection capable of providing aneutral connection to the at least one load and a third connectioncapable of providing a neutral connection to the at least one useraccessible load;

The circuit interrupting device also includes a circuit interruptingportion that is disposed within the housing and configured to causeelectrical discontinuity in one or both of the phase and neutralconductive paths, between said line side and said load side upon theoccurrence of a predetermined condition. A reset portion is disposed atleast partially within the housing and is configured to reestablishelectrical continuity in the open conductive paths.

Preferably, the phase conductive path includes a plurality of contactsthat are capable of opening to cause electrical discontinuity in thephase conductive path and closing to reestablish electrical continuityin the phase conductive path, between said line and load sides. Theneutral conductive path also includes a plurality of contacts that arecapable of opening to cause electrical discontinuity in the neutralconductive path and closing to reestablish electrical continuity in theneutral conductive path, between said line and load sides. In thisconfiguration, the circuit interrupting portion causes the plurality ofcontacts of the phase and neutral conductive paths to open, and thereset portion causes the plurality of contacts of the phase and neutralconductive paths to close.

One embodiment for the circuit interrupting portion uses anelectro-mechanical circuit interrupter to cause electrical discontinuityin the phase and neutral conductive paths, and sensing circuitry tosense the occurrence of the predetermined condition. For example, theelectro-mechanical circuit interrupter include a coil assembly, amovable plunger attached to the coil assembly and a banger attached tothe plunger. The movable plunger is responsive to energizing of the coilassembly, and movement of the plunger is translated to movement of saidbanger. Movement of the banger causes the electrical discontinuity inthe phase and/or neutral conductive paths.

The circuit interrupting device may also include reset lockout portionthat prevents the reestablishing of electrical continuity in either thephase or neutral conductive path or both conductive paths, unless thecircuit interrupting portion is operating properly. That is, the resetlockout prevents resetting of the device unless the circuit interruptingportion is operating properly. In embodiments where the circuitinterrupting device includes a reset lockout portion, the reset portionmay be configured so that at least one reset contact is electricallyconnected to the sensing circuitry of the circuit interrupting portion,and that depression of a reset button causes at least a portion of thephase conductive path to contact at least one reset contact. Whencontact is made between the phase conductive path and the at least onereset contact, the circuit interrupting portion is activated so that thereset lockout portion is disabled and electrical continuity in the phaseand neutral conductive paths can be reestablished.

The circuit interrupting device may also include a trip portion thatoperates independently of the circuit interrupting portion. The tripportion is disposed at least partially within the housing and isconfigured to cause electrical discontinuity in the phase and/or neutralconductive paths independent of the operation of the circuitinterrupting portion. In one embodiment, the trip portion includes atrip actuator accessible from an exterior of the housing and a trip armpreferably within the housing and extending from the trip actuator. Thetrip arm is preferably configured to facilitate mechanical breaking ofelectrical continuity in the phase and/or neutral conductive paths, ifthe trip actuator is actuated. Preferably, the trip actuator is abutton. However, other known actuators are also contemplated.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present application are described hereinwith reference to the drawings in which similar elements are givensimilar reference characters, wherein:

FIG. 1 is a perspective view of one embodiment of a ground fault circuitinterrupting device according to the present application;

FIG. 2 is side elevational view, partly in section, of a portion of theGFCI device shown in FIG. 1, illustrating the GFCI device in a set orcircuit making position;

FIG. 3 is an exploded view of internal components of the circuitinterrupting device of FIG. 1;

FIG. 4 is a plan view of portions of electrical conductive paths locatedwithin the GFCI device of FIG. 1;

FIG. 5 is a partial sectional view of a portion of a conductive pathshown in FIG. 4;

FIG. 6 is a partial sectional view of a portion of a conductive pathshown in FIG. 4;

FIG. 7 is a side elevational view similar to FIG. 2, illustrating theGFCI device in a circuit breaking or interrupting position;

FIG. 8 is a side elevational view similar to FIG. 2, illustrating thecomponents of the GFCI device during a reset operation;

FIGS. 9–11 are schematic representations of the operation of oneembodiment of the reset portion of the present application, illustratinga latching member used to make an electrical connection between line andload connections and to relate the reset portion of the electricalconnection with the operation of the circuit interrupting portion;

FIG. 12 is a schematic diagram of a circuit for detecting ground faultsand resetting the GFCI device of FIG. 1;

FIG. 13 is a perspective view of an alternative embodiment of a groundfault circuit interrupting device according to the present application;

FIG. 14 is side elevational view, partly in section, of a portion of theGFCI device shown in FIG. 13, illustrating the GFCI device in a set orcircuit making position;

FIG. 15 is a side elevational view similar to FIG. 14, illustrating theGFCI device in a circuit breaking position;

FIG. 16 is a side elevational view similar to FIG. 14, illustrating thecomponents of the GFCI device during a reset operation;

FIG. 17 is an exploded view of internal components of the GFCI device ofFIG. 13;

FIG. 18 is a schematic diagram of a circuit for detecting ground faultsand resetting the GFCI device of FIG. 13;

FIG. 19 is side elevational view, partly in section, of components of aportion of the alternative embodiment of the GFCI device shown in FIG.13, illustrating the device in a set or circuit making position;

FIG. 20 is a side elevational view similar to FIG. 19, illustrating ofthe device in a circuit breaking position; and

FIG. 21 is a block diagram of a circuit interrupting system according tothe present application.

DETAILED DESCRIPTION

The present application contemplates various types of circuitinterrupting devices that are capable of breaking at least oneconductive path at both a line side and a load side of the device. Theconductive path is typically divided between a line side that connectsto supplied electrical power and a load side that connects to one ormore loads. As noted, the various devices in the family of resettablecircuit interrupting devices include: ground fault circuit interrupters(GFCI's), arc fault circuit interrupters (AFCI's), immersion detectioncircuit interrupters (IDCI's), appliance leakage circuit interrupters(ALCI's) and equipment leakage circuit interrupters (ELCI's).

For the purpose of the present application, the structure or mechanismsused in the circuit interrupting devices, shown in the drawings anddescribed hereinbelow, are incorporated into a GFCI receptacle suitablefor installation in a single-gang junction box used in, for example, aresidential electrical wiring system. However, the mechanisms accordingto the present application can be included in any of the various devicesin the family of resettable circuit interrupting devices.

The GFCI receptacles described herein have line and load phase (orpower) connections, line and load neutral connections and useraccessible load phase and neutral connections. The connections permitexternal conductors or appliances to be connected to the device. Theseconnections may be, for example, electrical fastening devices thatsecure or connect external conductors to the circuit interruptingdevice, as well as conduct electricity. Examples of such connectionsinclude binding screws, lugs, terminals and external plug connections.

In one embodiment, the GFCI receptacle has a circuit interruptingportion, a reset portion and a reset lockout. This embodiment is shownin FIGS. 1–12. In another embodiment, the GFCI receptacle is similar tothe embodiment of FIGS. 1–12, except the reset lockout is omitted. Thus,in this embodiment, the GFCI receptacle has a circuit interruptingportion and a reset portion, which is similar to those described inFIGS. 1–12. In another embodiment, the GFCI receptacle has a circuitinterrupting portion, a reset portion, a reset lockout and anindependent trip portion. This embodiment is shown in FIGS. 13–20.

The circuit interrupting and reset portions described herein preferablyuse electro-mechanical components to break (open) and make (close) oneor more conductive paths between the line and load sides of the device.However, electrical components, such as solid state switches andsupporting circuitry, may be used to open and close the conductivepaths.

Generally, the circuit interrupting portion is used to automaticallybreak electrical continuity in one or more conductive paths (i.e., openthe conductive path) between the line and load sides upon the detectionof a fault, which in the embodiments described is a ground fault. Thereset portion is used to close the open conductive paths.

In the embodiments including a reset lockout, the reset portion is usedto disable the reset lockout, in addition to closing the open conductivepaths. In this configuration, the operation of the reset and resetlockout portions is in conjunction with the operation of the circuitinterrupting portion, so that electrical continuity in open conductivepaths cannot be reset if the circuit interrupting portion isnon-operational, if an open neutral condition exists and/or if thedevice is reverse wired.

In the embodiments including an independent trip portion, electricalcontinuity in one or more conductive paths can be broken independentlyof the operation of the circuit interrupting portion. Thus, in the eventthe circuit interrupting portion is not operating properly, the devicecan still be tripped.

The above-described features can be incorporated in any resettablecircuit interrupting device, but for simplicity the descriptions hereinare directed to GFCI receptacles.

Turning now to FIG. 1, the GFCI receptacle 10 has a housing 12consisting of a relatively central body 14 to which a face or coverportion 16 and a rear portion 18 are removably secured. The face portion16 has entry ports 20 and 21 for receiving normal or polarized prongs ofa male plug of the type normally found at the end of a lamp or appliancecord set (not shown), as well as ground-prong-receiving openings 22 toaccommodate a three-wire plug. The receptacle also includes a mountingstrap 24 used to fasten the receptacle to a junction box.

A test button 26 extends through opening 28 in the face portion 16 ofthe housing 12. The test button is used to activate a test operation,that tests the operation of the circuit interrupting portion (or circuitinterrupter) disposed in the device. The circuit interrupting portion,to be described in more detail below, is used to break electricalcontinuity in one or more conductive paths between the line and loadside of the device. A reset button 30 forming a part of the resetportion extends through opening 32 in the face portion 16 of the housing12. The reset button is used to activate a reset operation, whichreestablishes electrical continuity in the open conductive paths.

Electrical connections to existing household electrical wiring are madevia binding screws 34 and 36, where screw 34 is an input (or line) phaseconnection, and screw 36 is an output (or load) phase connection. Itshould be noted that two additional binding screws 38 and 40 (seen inFIG. 3) are located on the opposite side of the receptacle 10. Theseadditional binding screws provide line and load neutral connections,respectively. A more detailed description of a GFCI receptacle isprovided in U.S. Pat. No. 4,595,894, which is incorporated herein in itsentirety by reference. It should also be noted that binding screws 34,36, 38 and 40 are exemplary of the types of wiring terminals that can beused to provide the electrical connections. Examples of other types ofwiring terminals include set screws, pressure clamps, pressure plates,push-in type connections, pigtails and quick-connect tabs.

Referring to FIGS. 2–6, the conductive path between the line phaseconnection 34 and the load phase connection 36 includes contact arm 50which is movable between stressed and unstressed positions, movablecontact 52 mounted to the contact arm 50, contact arm 54 secured to ormonolithically formed into the load phase connection 36 and fixedcontact 56 mounted to the contact arm 54. The user accessible load phaseconnection for this embodiment includes terminal assembly 58 having twobinding terminals 60 which are capable of engaging a prong of a maleplug inserted therebetween. The conductive path between the line phaseconnection 34 and the user accessible load phase connection includes,contact arm 50, movable contact 62 mounted to contact arm 50, contactarm 64 secured to or monolithically formed into terminal assembly 58,and fixed contact 66 mounted to contact arm 64. These conductive pathsare collectively called the phase conductive path.

Similarly, the conductive path between the line neutral connection 38and the load neutral connection 40 includes, contact arm 70 which ismovable between stressed and unstressed positions, movable contact 72mounted to contact arm 70, contact arm 74 secured to or monolithicallyformed into load neutral connection 40, and fixed contact 76 mounted tothe contact arm 74. The user accessible load neutral connection for thisembodiment includes terminal assembly 78 having two binding terminals 80which are capable of engaging a prong of a male plug insertedtherebetween. The conductive path between the line neutral connection 38and the user accessible load neutral connection includes, contact arm70, movable contact 82 mounted to the contact arm 70, contact arm 84secured to or monolithically formed into terminal assembly 78, and fixedcontact 86 mounted to contact arm 84. These conductive paths arecollectively called the neutral conductive path.

Referring to FIG. 2, the circuit interrupting portion has a circuitinterrupter and electronic circuitry capable of sensing faults, e.g.,current imbalances, on the hot and/or neutral conductors. In a preferredembodiment for the GFCI receptacle, the circuit interrupter includes acoil assembly 90, a plunger 92 responsive to the energizing andde-energizing of the coil assembly and a banger 94 connected to theplunger 92. The banger 94 has a pair of banger dogs 96 and 98 whichinteract with a movable latching members 100 used to set and resetelectrical continuity in one or more conductive paths. The coil assembly90 is activated in response to the sensing of a ground fault by, forexample, the sense circuitry shown in FIG. 12. FIG. 12 showsconventional circuitry for detecting ground faults that includes adifferential transformer that senses current imbalances.

The reset portion includes reset button 30, the movable latching members100 connected to the reset button 30, latching fingers 102 and resetcontacts 104 and 106 that temporarily activate the circuit interruptingportion when the reset button is depressed, when in the trippedposition. Preferably, the reset contacts 104 and 106 are normally openmomentary contacts. The latching fingers 102 are used to engage side Rof each contact arm 50,70 and move the arms 50,70 back to the stressedposition where contacts 52,62 touch contacts 56,66, respectively, andwhere contacts 72,82 touch contacts 76,86, respectively.

The movable latching members 102 are, in this embodiment, common to eachportion (i.e., the circuit interrupting, reset and reset lockoutportions) and used to facilitate making, breaking or locking out ofelectrical continuity of one or more of the conductive paths. However,the circuit interrupting devices according to the present applicationalso contemplate embodiments where there is no common mechanism ormember between each portion or between certain portions. Further, thepresent application also contemplates using circuit interrupting devicesthat have circuit interrupting, reset and reset lockout portions tofacilitate making, breaking or locking out of the electrical continuityof one or both of the phase or neutral conductive paths.

In the embodiment shown in FIGS. 2 and 3, the reset lockout portionincludes latching fingers 102 which after the device is tripped, engagesside L of the movable arms 50,70 so as to block the movable arms 50,70from moving. By blocking movement of the movable arms 50,70, contacts 52and 56, contacts 62 and 66, contacts 72 and 76 and contacts 82 and 86are prevented from touching. Alternatively, only one of the movable arms50 or 70 may be blocked so that their respective contacts are preventedfrom touching. Further, in this embodiment, latching fingers 102 act asan active inhibitor that prevents the contacts from touching.Alternatively, the natural bias of movable arms 50 and 70 can be used asa passive inhibitor that prevents the contacts from touching.

Referring now to FIGS. 2 and 7–11, the mechanical components of thecircuit interrupting and reset portions in various stages of operationare shown. For this part of the description, the operation will bedescribed only for the phase conductive path, but the operation issimilar for the neutral conductive path, if it is desired to open andclose both conductive paths. In FIG. 2, the GFCI receptacle is shown ina set position where movable contact arm 50 is in a stressed conditionso that movable contact 52 is in electrical engagement with fixedcontact 56 of contact arm 54. If the sensing circuitry of the GFCIreceptacle senses a ground fault, the coil assembly 90 is energized todraw plunger 92 into the coil assembly 90 so that banger 94 movesupwardly. As the banger moves upwardly, the banger front dog 98 strikesthe latch member 100 causing it to pivot in a counterclockwise directionC (seen in FIG. 7) about the joint created by the top edge 112 and innersurface 114 of finger 110. The movement of the latch member 100 removesthe latching finger 102 from engagement with side R of the remote end116 of the movable contact arm 50, and permits the contact arm 50 toreturn to its pre-stressed condition opening contacts 52 and 56, seen inFIG. 7.

After tripping, the coil assembly 90 is de-energized so that spring 93returns plunger 92 to its original extended position and banger 94 movesto its original position releasing latch member 100. At this time, thelatch member 100 is in a lockout position where latch finger 102inhibits movable contact 52 from engaging fixed contact 56, as seen inFIG. 10. As noted, one or both latching fingers 102 can act as an activeinhibitor that prevents the contacts from touching. Alternatively, thenatural bias of movable arms 50 and 70 can be used as a passiveinhibitor that prevents the contacts from touching.

To reset the GFCI receptacle so that contacts 52 and 56 are closed andcontinuity in the phase conductive path is reestablished, the resetbutton 30 is depressed sufficiently to overcome the bias force of returnspring 120 and move the latch member 100 in the direction of arrow A,seen in FIG. 8. While the reset button 30 is being depressed, latchfinger 102 contacts side L of the movable contact arm 50 and continueddepression of the reset button 30 forces the latch member to overcomethe stress force exerted by the arm 50 causing the reset contact 104 onthe arm 50 to close on reset contact 106. Closing the reset contactsactivates the operation of the circuit interrupter by, for examplesimulating a fault, so that plunger 92 moves the banger 94 upwardlystriking the latch member 100 which pivots the latch finger 102, whilethe latch member 100 continues to move in the direction of arrow A. As aresult, the latch finger 102 is lifted over side L of the remote end 116of the movable contact arm 50 onto side R of the remote end of themovable contact arm, as seen in FIGS. 7 and 11. Contact arm 50 returnsto its unstressed position, opening contacts 52 and 56 and contacts 62and 66, so as to terminate the activation of the circuit interruptingportion, thereby de-energizing the coil assembly 90.

After the circuit interrupter operation is activated, the coil assembly90 is de-energized so that so that plunger 92 returns to its originalextended position, and banger 94 releases the latch member 100 so thatthe latch finger 102 is in a reset position, seen din FIG. 9. Release ofthe reset button causes the latching member 100 and movable contact arm50 to move in the direction of arrow B (seen in FIG. 9) until contact 52electrically engages contact 56, as seen in FIG. 2.

As noted above, if opening and closing of electrical continuity in theneutral conductive path is desired, the above description for the phaseconductive path is also applicable to the neutral conductive path.

In an alternative embodiment, the circuit interrupting devices may alsoinclude a trip portion that operates independently of the circuitinterrupting portion so that in the event the circuit interruptingportion becomes non-operational the device can still be tripped.Preferably, the trip portion is manually activated and uses mechanicalcomponents to break one or more conductive paths. However, the tripportion may use electrical circuitry and/or electro-mechanicalcomponents to break either the phase or neutral conductive path or bothpaths.

For the purposes of the present application, the structure or mechanismsfor this embodiment are also incorporated into a GFCI receptacle, seenin FIGS. 13–20, suitable for installation in a single-gang junction boxin a home. However, the mechanisms according to the present applicationcan be included in any of the various devices in the family ofresettable circuit interrupting devices.

Turning now to FIG. 13, the GFCI receptacle 200 according to thisembodiment is similar to the GFCI receptacle described in FIGS. 1–12.Similar to FIG. 1, the GFCI receptacle 200 has a housing 12 consistingof a relatively central body 14 to which a face or cover portion 16 anda rear portion 18 are, preferably, removably secured.

A trip actuator 202, preferably a button, which is part of the tripportion to be described in more detail below, extends through opening 28in the face portion 16 of the housing 12. The trip actuator is used, inthis exemplary embodiment, to mechanically trip the GFCI receptacle,i.e., break electrical continuity in one or more of the conductivepaths, independent of the operation of the circuit interrupting portion.

A reset actuator 30, preferably a button, which is part of the resetportion, extends through opening 32 in the face portion 16 of thehousing 12. The reset button is used to activate the reset operation,which re-establishes electrical continuity in the open conductive paths,i.e., resets the device, if the circuit interrupting portion isoperational.

As in the above embodiment, electrical connections to existing householdelectrical wiring are made via binding screws 34 and 36, where screw 34is an input (or line) phase connection, and screw 36 is an output (orload) phase connection. It should be noted that two additionalbinding-screws 38 and 40 (seen in FIG. 3) are located on the oppositeside of the receptacle 200. These additional binding screws provide lineand load neutral connections, respectively. A more detailed descriptionof a GFCI receptacle is provided in U.S. Pat. No. 4,595,894, which isincorporated herein in its entirety by reference.

Referring to FIGS. 4–6, 14 and 17, the conductive paths in thisembodiment are substantially the same as those described above. Theconductive path between the line phase connection 34 and the load phaseconnection 36 includes, contact arm 50 which is movable between stressedand unstressed positions, movable contact 52 mounted to the contact arm50, contact arm 54 secured to or monolithically formed into the loadphase connection 36 and fixed contact 56 mounted to the contact arm 54(seen in FIGS. 4, 5 and 17). The user accessible load phase connectionfor this embodiment includes terminal assembly 58 having two bindingterminals 60 which are capable of engaging a prong of a male pluginserted therebetween. The conductive path between the line phaseconnection 34 and the user accessible load phase connection includes,contact arm 50, movable contact 62 mounted to contact arm 50, contactarm 64 secured to or monolithically formed into terminal assembly 58,and fixed contact 66 mounted to contact arm 64. These conductive pathsare collectively called the phase conductive path.

Similarly, the conductive path between the line neutral connection 38and the load neutral connection 40 includes, contact arm 70 which ismovable between stressed and unstressed positions, movable contact 72mounted to contact arm 70, contact arm 74 secured to or monolithicallyformed into load neutral connection 40, and fixed contact 76 mounted tothe contact arm 74 (seen in FIGS. 4, 6 and 17). The user accessible loadneutral connection for this embodiment includes terminal assembly 78having two binding terminals 80 which are capable of engaging a prong ofa male plug inserted therebetween. The conductive path between the lineneutral connection 38 and the user accessible load neutral connectionincludes, contact arm 70, movable contact 82 mounted to the contact arm70, contact arm 84 secured to or monolithically formed into terminalassembly 78, and fixed contact 86 mounted to contact arm 84. Theseconductive paths are collectively called the neutral conductive path.

There is also shown in FIG. 14, mechanical components used duringcircuit interrupting and reset operations according to this embodimentof the present application. Although these components shown in thedrawings are electro-mechanical in nature, the present application alsocontemplates using semiconductor type circuit interrupting and resetcomponents, as well as other mechanisms capable of making and breakingelectrical continuity.

The circuit interrupting device according to this embodimentincorporates an independent trip portion into the circuit interruptingdevice of FIGS. 1–12. Therefore, a description of the circuitinterrupting, reset and reset lockout portions are omitted.

Referring to FIGS. 14–16 an exemplary embodiment of the trip portionaccording to the present application includes a trip actuator 202,preferably a button, that is movable between a set position, wherecontacts 52 and 56 are permitted to close or make contact, as seen inFIG. 14, and a trip position where contacts 52 and 56 are caused toopen, as seen in FIG. 15. Spring 204 normally biases trip actuator 202toward the set position. The trip portion also includes a trip arm 206that extends from the trip actuator 202 so that a surface 208 of thetrip arm 206 moves into contact with the movable latching member 100,when the trip button is moved toward the trip position. When the tripactuator 202 is in the set position, surface 208 of trip arm 202 can bein contact with or close proximity to the movable latching member 100,as seen in FIG. 14.

In operation, upon depression of the trip actuator 202, the tripactuator pivots about point T of pivot arm 210 (seen in FIG. 15)extending from strap 24 so that the surface 208 of the trip arm 206 cancontact the movable latching member 100. As the trip actuator 202 ismoved toward the trip position, trip arm 206 also enters the path ofmovement of the finger 110 associated with reset button 30 thus blockingthe finger 102 from further movement in the direction of arrow A (seenin FIG. 15). By blocking the movement of the finger 110, the trip arm206 inhibits the activation of the reset operation and, thus, inhibitssimultaneous activation of the trip and reset operations. Furtherdepression of the trip actuator 202 causes the movable latching member100 to pivot about point T in the direction of arrow C (seen in FIG.15). Pivotal movement of the latching member 100 causes latching finger102 of latching arm 100 to move out of contact with the movable contactarm 50 so that the arm 50 returns to its unstressed condition, and theconductive path is broken. Resetting of the device is achieved asdescribed above. An exemplary embodiment of the circuitry used to sensefaults and reset the conductive paths, is shown in FIG. 18.

As noted above, if opening and closing of electrical continuity in theneutral conductive path is desired, the above description for the phaseconductive path is also applicable to the neutral conductive path.

An alternative embodiment of the trip portion will be described withreference to FIGS. 19 and 20. In this embodiment, the trip portionincludes a trip actuator 202 that at is movable between a set position,where contacts 52 and 56 are permitted to close or make contact, as seenin FIG. 19, and a trip position where contacts 52 and 56 are caused toopen, as seen in FIG. 20. Spring 220 normally biases trip actuator 202toward the set position. The trip portion also includes a trip arm 224that extends from the trip actuator 202 so that a distal end 226 of thetrip arm is in movable contact with the movable latching member 100. Asnoted above, the movable latching member 100 is, in this embodiment,common to the trip, circuit interrupting, reset and reset lockoutportions and is used to make, break or lockout the electricalconnections in the phase and/or neutral conductive paths.

In this embodiment, the movable latching member 100 includes a rampedportion 100 a which facilitates opening and closing of electricalcontacts 52 and 56 when the trip actuator 202 is moved between the setand trip positions, respectively. To illustrate, when the trip actuator202 is in the set position, distal end 226 of trip arm 224 contacts theupper side of the ramped portion 10 a, seen in FIG. 19. When the tripactuator 202 is depressed, the distal end 226 of the trip arm 224 movesalong the ramp and pivots the latching member 60 about point P in thedirection of arrow C causing latching finger 102 of the latching member100 to move out of contact with the movable contact arm 50 so that thearm 50 returns to its unstressed condition, and the conductive path isbroken. Resetting of the device is achieved as described above.

The circuit interrupting device according to the present application canbe used in electrical systems, shown in the exemplary block diagram ofFIG. 21. The system 240 includes a source of power 242, such as ac powerin a home, at least one circuit interrupting device, e.g., circuitinterrupting device 10 or 200, electrically connected to the powersource, and one or more loads 244 connected to the circuit interruptingdevice. As an example of one such system, ac power supplied to singlegang junction box in a home may be connected to a GFCI receptacle havingone of the above described reverse wiring fault protection, independenttrip or reset lockout features, or any combination of these features maybe combined into the circuit interrupting device. Household appliancesthat are then plugged into the receptacle become the load or loads ofthe system.

As noted, although the components used during circuit interrupting anddevice reset operations are electro-mechanical in nature, the presentapplication also contemplates using electrical components, such as solidstate switches and supporting circuitry, as well as other types ofcomponents capable or making and breaking electrical continuity in theconductive path.

While there have been shown and described and pointed out thefundamental features of the invention, it will be understood thatvarious omissions and substitutions and changes of the form and detailsof the device described and illustrated and in its operation may be madeby those skilled in the art, without departing from the spirit of theinvention.

1. A circuit interrupting device comprising: a first electricalconductor; a second electrical conductor; a third electrical conductorwhere the first, second and third electrical conductors are electricallyisolated from each other and at least one of said conductors is capableof electrically connecting with the other two conductors such that thefirst, second and third electrical conductors are electrically connectedto each other; and a circuit interrupting portion positioned toelectrically disconnect the first, second and third electricalconductors from each other upon the occurrence of a predeterminedcondition.
 2. The circuit interrupting device of claim 1 where the firstelectrical conductor is capable of being electrically connected to asource of electricity, the second electrical conductor is capable ofconducting electrical current to a load when electrically connected tothe first electrical conductor and the third electrical conductor iscapable of being electrically connected to a user accessible load. 3.The circuit interrupting device of claim 1 where the circuitinterrupting portion has a circuit interrupter and the device furtherhas a reset button which when depressed is either capable of activatingat least a portion of the circuit interrupter to reestablish electricalcontinuity between the first, second and third electrical conductors oris not capable of activating the at least portion of the circuitinterrupter preventing the device from reestablishing electricalcontinuity between the first second and third electrical conductors. 4.The circuit interrupting device of claim 1 where the circuitinterrupting portion has a circuit interrupter and the device furtherhas a reset button which when depressed is capable of activating atleast a portion of the circuit interrupter to reestablish electricalcontinuity between the first second and third electrical conductors ifelectrical current is made available to activate the at least portion ofthe circuit interrupter when pressing the reset button.
 5. The circuitinterrupting device of claim 4 where the at least portion of the circuitinterrupter is a plunger responsive to energizing and de-energizing of acoil.
 6. The circuit interrupting device of claim 3 where the at leastportion of the circuit interrupter is a plunger responsive to energizingand de-energizing of a coil.
 7. The circuit interrupting device of claim3 where the reestablishment of electrical continuity between the first,second and third electrical conductors is prevented if the circuitinterrupting device is reverse wired.
 8. The circuit interrupting deviceof claim 3 where the reestablishment of electrical continuity betweenthe first, second and third electrical conductors is prevented if anopen neutral condition exists.
 9. The circuit interrupting device ofclaim 3 where the circuit interrupter has at least a coil and plungerassembly and electronic circuitry capable of sensing a predeterminedcondition.
 10. The circuit interrupting device of claim 3 where at leastone of the conductors moves to either reestablish electrical continuitybetween the first, second an third electrical conductors or electricallydisconnect the first, second and third electrical conductors from eachother.
 11. The circuit interrupting device of claim 1 where at least oneof the conductors is movable.
 12. The circuit interrupting device ofclaim 1 where the predetermined condition comprises a ground fault, anarc fault, an appliance leakage fault, an equipment leakage fault, animmersion fault and a test cycle.
 13. A circuit interrupting devicecomprising: a first electrical conductor; a second electrical conductor;a third electrical conductor the first, second and third electricalconductors having a first spatial arrangement wherein said conductorsare all electrically connected with each other and a second spatialarrangement wherein said first, second and third electrical conductorsare all electrically isolated from each other; and an electrical faultsensor and an electro-mechanical actuator connected and disposed tochange the spatial arrangement of said conductors from said firstspatial arrangement to said second spatial arrangement upon theoccurrence of an electrical fault.
 14. A circuit interrupting device asin claim 13 further comprising a reset assembly disposed to change thespatial arrangement of said first, second and third conductors from saidsecond arrangement to said first arrangement.
 15. A circuit interruptingdevice as in claim 13 wherein at least two of said conductors areelectrically connected to respectively corresponding external electricalcircuits and said electrical fault sensor is connected to sense anelectrical fault in at least one of said external circuits.
 16. Acircuit interrupting device as in claim 13 further comprising: a latchdisposed to maintain said second arrangement when changed thereto fromsaid first arrangement; and a manually operable user-accessible circuitreset switch which is electrically connected to an electro-mechanicalactuator disposed to unlatch said second spatial arrangement and tochange the spatial arrangement of said conductors to said first spatialarrangement upon user actuation of said reset switch which is connectedto complete a circuit with an externally accessible line terminal ofsaid device.
 17. A circuit interrupting device as in claim 16 wherein: acommon electro-mechanical actuator is used to change the arrangement ofsaid first second and third conductors between said first and secondarrangements; and said reset switch is electrically connected to createa simulated fault condition within said device when actuated whichcauses electrical energization of said common electro-mechanicalactuator.
 18. A circuit interrupting device as in claim 17 wherein saidelectro-mechanical actuator is disposed to interact with a latch coupledto at least one of said conductors, said latch being configured anddisposed (a) to latch said first spatial arrangement until automaticallyunlatched and changed to said second spatial arrangement upon occurrenceof a fault condition and thereafter (b) to automatically latch saidsecond spatial arrangement until unlatched and by user action re-set andre-latched to said first spatial arrangement.
 19. A circuit interruptingdevice as in claim 18 wherein said latch comprises a mechanical latchmember.
 20. A method for insuring safe operation of a circuitinterrupting device having first, second and third electrical conductorsadapted for respective electrical connection to external line, load anduser circuits, said method comprising: moving at least one of saidfirst, second and third electrical conductors to place them into a firstspatial arrangement in which said conductors are all electricallyconnected with each other; detecting an electrical fault, and upon theoccurrence of said electrical fault automatically moving at least one ofsaid first, second and third conductors into a second spatialarrangement in which said conductors are all electrically isolated fromone another.
 21. A method as in claim 20 further comprising: in responseto user action, moving at least one of said conductors to reset saidfirst, second and third conductors from said second configuration tosaid first configuration.
 22. A method as in claim 20 furthercomprising: latching said at least one movable conductor in place tomaintain said first spatial arrangement until occurrence of said faultcondition whereupon said at least one conductor is unlatched and movedto establish said second spatial arrangement; and automatically latchingsaid at least one movable conductor in place to maintain said secondspatial arrangement until occurrence of user action unlatching andre-setting of said at least one conductor to said first spatialarrangement.
 23. A circuit interrupting device comprising: a firstelectrical line conductor including an electrical line connectionterminal accessible externally of said device and at least oneelectrical contact located internally of said device; a secondelectrical load conductor including an electrical load connectionterminal accessible externally of said device and at least oneelectrical contact located internally of said device; a third electricalface conductor including at least one user-accessible electrical socketconnector terminal accessible to a user-installed connecting plug fromthe external face of the device and at least one electrical contactlocated internally of said device; at least one of the internallylocated electrical contacts of said first, second and third electricalconductors being movable between (a) a first spatial arrangement whereinsaid conductors are all electrically connected with each other and (b) asecond spatial arrangement wherein said first, second and thirdelectrical conductors are all electrically isolated from with eachother; an electrical fault sensor electrically coupled to at least oneof said conductors, and an electro-mechanical operator which iselectrically coupled to said fault sensor and mechanically coupled toautomatically effect movement of said at least one movable electricalcontact from said first configuration to said second configuration uponthe occurrence of an electrical fault sensed by said fault sensor.
 24. Acircuit interrupting device as in claim 23 further comprising: amanually operable reset actuator accessible from the exterior of saiddevice, and a reset assembly coupled to said reset actuator and disposedto move said at least one movable electrical contact from said secondconfiguration to said first configuration upon user operation of saidreset actuator.
 25. A circuit interrupting device as in claim 24wherein: said reset assembly includes an electro-mechanical operatorelectrically coupled to said line conductor and to an electrical switchcontact operated by said reset actuator, said reset assembly also beingmechanically coupled to change said at least one movable electricalcontact from said second spatial arrangement to said first spatialarrangement upon operation of said reset actuator.
 26. A circuitinterrupting device as in claim 25 wherein said electro-mechanicaloperator is configured and disposed to (a) automatically unlatch said atleast one contact and effect change from said first to said secondspatial arrangement upon occurrence of an electrical fault and (b)unlatch said at least one contact and effect change from said secondspatial arrangement to said first spatial arrangement upon user resetaction.
 27. A method for insuring safe operation of a circuitinterrupting device having external electrical line, load anduser-accessible face electrical connections, said method comprising:providing separate first, second and third electrical conductorstructures for said external electrical line, load and user-accessibleface connections respectively, each of said conductor structuresincluding at least one electrical contact located internally of saiddevice and at least one of said internal electrical contacts beingmounted movably with respect to the remainder of the contact(s) between(a) a first spatial arrangement wherein said internal conductor contactsand conductor structures are all electrically connected with each otherand (b) a second spatial arrangement wherein said internal conductorcontacts and said electrical conductor structures are all electricallyisolated from each other; placing and latching said at least one movableelectrical contact into said first spatial arrangement in which saidconductors are all electrically connected with each other; automaticallydetecting an electrical fault, automatically unlatching and placing saidat least one movable electrical contact into said second spatialarrangement in which said conductors are all electrically isolated fromone another upon the occurrence of said detected electrical fault; andautomatically latching said at least one movable electrical contact insaid second spatial arrangement.
 28. A method as in claim 27 wherein atleast two of said conductors are connected to respectively correspondingexternal electrical circuits and said electrical fault is present in atleast one of said external circuits.
 29. A method as in claim 27 furthercomprising: re-setting and re-latching said at least one movable contactfrom said second spatial arrangement to said first spatial arrangementin response to manual user action.
 30. A method as in claim 29 whereinsaid placing, latching and resetting steps are each performed using, atleast in part, the same electro-mechanical operator.
 31. A method as inclaim 30 wherein: said electro-mechanical operator is (a) automaticallyelectrically energized by a fault detector that is electrically coupledto said externally accessible connections and (b) manually electricallyenergized by an electrical switch operated by an externally accessibleuser-operated reset actuator; and said electro-mechanical operator isconfigured and disposed to mechanically move a latch member.
 32. Acircuit interrupting device for installation in a three-wire electricalcircuit having phase, neutral and ground conductor wires feedingelectricity from a source line circuit to at least one downstream loadcircuit, said circuit interrupting device comprising: a non-conductivehousing having upper and lower mounting flanges and a user-accessiblefront face presenting a pair of female electrical sockets, each sockethaving three-recesses with conductive connection terminals respectivelyconfigured for user-controlled connection to phase, neutral and groundmale terminals of at least one electrical load plug, said housing alsohaving an installer-accessible body presenting (a) a first pair ofconductive connection terminals adapted for respective electricalconnection to line and load phase wires, (b) a second pair of conductiveconnection terminals adapted for respective electrical connection toline and load neutral wires, and (c) at least one third conductiveconnection terminal adapted for electrical connection to at least oneground wire; a trio of first electrical conductors disposed internallyof said housing and respectively electrically connected to theconductive phase connection terminals; a trio of second electricalconductors disposed internally of said housing and respectivelyelectrically connected to the conductive neutral connection terminals;said trio of first electrical conductors having a first spatialarrangement wherein said trio of first electrical conductors are allelectrically connected with each other and a second spatial arrangementwherein said trio of first electrical conductors are all electricallyisolated from each other; said trio of second electrical conductorshaving a first spatial arrangement wherein said trio of secondelectrical conductors are all electrically connected with each other anda second spatial arrangement wherein said trio of second electricalconductors are all electrically isolated from each other; and anelectrical fault sensor and an electro-mechanical actuator connected anddisposed to change the spatial arrangement of said trios of conductorsrespectively from said first spatial arrangement to said second spatialarrangement upon the occurrence of an electrical fault.
 33. A circuitinterrupting device as in claim 32 further comprising a reset assemblydisposed to change the spatial arrangement of said trios of conductorsrespectively from said second arrangement to said first arrangement. 34.A circuit interrupting device as in claim 32 wherein said reset assemblyis electrically connected with the line phase terminal and comprises: amanually operable electrical reset switch, and an electro-mechanicaltransducer electrically connected with said reset switch andmechanically coupled to cause reconfiguration of both said trios ofconductors from said second arrangement to said first arrangement whensaid reset switch is operated.
 35. A circuit interrupting device as inclaim 32 further comprising: latch disposed to maintain both said triosin their respective second arrangements when changed thereto from saidfirst arrangements; and a manually operable user-accessible circuitreset switch which is electrically connected to an electro-mechanicalactuator disposed to unlatch said second spatial arrangements and tochange the spatial arrangements of said trios of conductors to saidfirst spatial arrangements upon user actuation of said reset switchwhich is connected to complete a circuit connected to the line phaseterminal.
 36. A circuit interrupting device as in claim 35 wherein: acommon electro-mechanical actuator is used to change the arrangements ofsaid trios of conductors between said first and second arrangements; andsaid reset switch is electrically connected to create a simulated faultcondition within said device when actuated which causes electricalenergization of said common electro-mechanical actuator.
 37. A circuitinterrupting device as in claim 36 wherein said electro-mechanicalactuator is disposed to interact with a latch coupled to at least oneconductor of each of said trios, said latch being configured anddisposed (a) to latch said first spatial arrangements until unlatchedand changed to said second spatial arrangements upon occurrence of afault condition and thereafter (b) to latch said second spatialarrangements until unlatched and by user action re-set and re-latched tosaid first spatial arrangements.
 38. A circuit interrupting device as inclaim 37 wherein said latch comprises at least one mechanical latchmember.
 39. A method for insuring safe operation of a circuitinterrupting device adapted for installation in a three-wire electricalcircuit having phase, neutral and ground conductor wires feedingelectricity from a source line circuit to at least one downstream loadcircuit, said method comprising: moving a trio of first electricalconductors to place them into a first spatial arrangement in which theyare all electrically connected with each other, said trio of firstelectrical conductors being respectively electrically connected to atleast one user-accessible phase terminal, an installer-accessible phaseline terminal, and an installer-accessible phase load terminal; moving atrio of second electrical conductors to place them into a first spatialarrangement in which they are all electrically connected with eachother, said trio of second electrical conductors being respectivelyelectrically connected to at least one user-accessible neutral terminal,an installer-accessible neutral line terminal, and aninstaller-accessible neutral load terminal; detecting an electricalfault, and upon the occurrence of said electrical fault, automaticallymoving said trios of conductors into respective second spatialarrangements in which the conductors of each trio are all electricallyisolated from one another.
 40. A method as in claim 39 furthercomprising: in response to user action, moving at least one conductor ineach of said trios to reset said trios from said second arrangements tosaid first arrangements.
 41. A method as in claim 39 further comprising:latching said at least one movable conductor of each trio in place tomaintain said first spatial arrangements until occurrence of said faultcondition whereupon said at least one conductor of each trio isautomatically unlatched and moved to establish said second spatialarrangements; and automaticafly latching said at least one movableconductor of each trio in place to maintain said second spatialarrangements until occurrence of user action unlatching and re-sellingof said at least one conductor of each trio to said first spatialarrangements.
 42. A method for insuring safe operation of a circuitinterrupting device having, for each of phase and neutral circuitconnections, external electrical line, load and user-accessible faceelectrical connections, said method comprising: providing for phaseconnections to separate first, second and third electrical conductorstructures for said external electrical line, load and user-accessibleface connections respectively, each of said conductor structuresincluding at least one electrical contact located internally of saiddevice and at least one of said internal electrical contacts beingmounted movably with respect to the remainder of the contact(s) between(a) a first spatial arrangement wherein said internal conductor contactsand conductor structures are all electrically connected with each otherand (b) a second spatial arrangement wherein said internal conductorcontacts and said electrical conductor structures are all electricallyisolated from each other; providing for neutral connections to separatefirst, second and third electrical conductor structures for saidexternal electrical line, load and user-accessible face connectionsrespectively, each of said conductor structures including at least oneelectrical contact located internally of said device and at least one ofsaid internal electrical contacts being mounted movably with respect tothe remainder of the contact(s) between (a) a first spatial arrangementwherein said internal conductor contacts and conductor structures areall electrically connected with each other and (b) a second spatialarrangement wherein said internal conductor contacts and said electricalconductor structures are all electrically isolated from each other;placing and latching said at least one movable electrical contacts intosaid first spatial arrangements in which said phase conductors are allelectrically connected with each other and said neutral conductors areall electrically connected with each other; automatically detecting anelectrical fault, automatically unlatching and placing said at least onemovable electrical contacts into said second spatial arrangements inwhich said phase conductors are all electrically isolated from oneanother and said neutral conductors are all electrically isolated fromone another upon the occurrence of said detected electrical fault; andautomatically latching said at least one movable electrical contacts insaid second spatial arrangements.
 43. A method as in claim 42 furthercomprising: re-setting and re-latching said at least one movablecontacts from said second spatial arrangements to said first spatialarrangements in response to manual user action.
 44. A method as in claim43 wherein said placing, latching and resetting steps are each performedusing, at least in part, the same electro-mechanical operator.
 45. Amethod as in claim 44 wherein: said electro-mechanical operator is (a)automatically electrically energized by a fault detector that iselectrically coupled to said installer-accessible connections and (b)manually electrically energized by an electrical switch operated by anexternally accessible user-operated reset actuator; and saidelectro-mechanical operator is configured and disposed to mechanicallymove a latch member.